Documentation for DLP, as well as announcements from Symantec (cf. TECH220042), confirm that SharePoint 2013 is a supported target for DLP Network Discover.
However, the implementation of the SharePoint Quarantine FlexResponse PlugIn cannot be installed into the SharePoint 2013 environment.
On install to a SharePoint 2013 server the following error is returned: "Windows SharePoint Services 3.0 / SharePoint 2010 Foundation is NOT installed!"
Owing to changes in the libraries for SharePoint 2013, the DLP Quarantine FlexResponse solution is not compatible with SharePoint 2013.
The documentation Symantec DLP SharePoint Quarantine FlexResponse Plug-in Implementation Guide confirms that only SharePoint 2007 and 2010 are supported for the Quarantine Flex Response solution.
Support for SharePoint 2013 will be provided in a future release of the SharePoint Quarantine FlexResponse Plug-in.